On the effects of component durations and component reinforcement rates in multiple schedules

Four experiments, each using the same six pigeons, investigated the effects of varying component durations and component reinforcement rates in multiple variable-interval schedules. Experiment 1 used unequal component durations in which one component was five times the duration of the other, and the shorter component was varied over conditions from 120 seconds to 5 seconds. The schedules were varied over five values for each pair of component durations. Sensitivity to reinforcement rate changes was the same at all component durations. In Experiment 2, both component durations were 5 seconds, and the schedules were again varied using both one and two response keys. Sensitivity to reinforcement was not different from the values found in Experiment 1. In Experiment 3, various manipulations, including body-weight changes, reinforcer duration changes, blackouts, hopper lights correlated with keylights, and overall reinforcement rate changes were carried out. No reliable increase in reinforcement sensitivity resulted from any manipulation. Finally, in Experiment 4, reinforcement rates in the two components were kept constant and unequal, and the component durations were varied. Shorter components produced significantly increased response rates normally in the higher reinforcement rate component, but schedule reversals at short component durations eliminated the response rate increases. The effects of component duration on multiple schedule performance cannot be interpreted as changing sensitivity to reinforcement nor to changing bias.     

Effects of component length and of the transitions among components in multiple schedules

Pigeons received equal variable-interval reinforcement during presentations of two line-orientation stimuli while five other orientations appeared in extinction. Component duration was 30 seconds for all orientations and the sequence was arranged so that each orientation preceded itself and each other orientation equally often. The duration of one component (0°) was shortened to 10 seconds and the other (90°) was lengthened to 50 seconds. All animals showed large increases in response rate in the shortened component and this increase was recoverable after an interpolated condition in which all components were again 30 seconds in duration. This effect was replicated in a second experiment in which component duration was changed from 150 seconds to 50 seconds and 250 seconds. An examination of local contrast effects during the first experiment showed that the shortened component produced local contrast during subsequent presentations of the lengthened component, just as would a component associated with more frequent reinforcement. When the presentation sequence was changed so that the lengthened component was always followed by the shortened component, response rates generally increased during the lengthened component. When the sequence was arranged so that the shortened component always preceded the longer component, response rate decreased in the former. These effects, as well as the increases in response rate following change in component length, seem not to be the product of local contrast effects among components.     

Undermatching and contrast within components of multiple schedules

Six multiple variable-interval schedules each comprised one variable-interval sixty second component and an alternated component which was varied. Four pigeons' responses were recorded in five successive subintervals of each component. Response rate changes across subintervals revealed instances of local contrast and small local induction effects in the changed component. In the constant component, smaller local contrast and larger local induction effects obtained. Accordingly, the magnitude of behavioral contrast, defined as an inverse relation between response rate in the constant component and reinforcement rate in the changed component, did not change reliably across subintervals of the constant component. Ratios of response rates in initial subintervals were highly sensitive to reinforcement ratios. Sensitivity decreased sharply over the first two-fifths of the components and remained constant for the remainder. The results demonstrated that changes in multiple schedule sensitivity are a function of time since the alternation of successive components.     

The effects of different component response requirements in multiple and concurrent schedules

Six pigeons were trained on multiple and concurrent schedules. The reinforcement rates were varied systematically (a) when lever pressing was required in one component and key pecking in the successive component; (b) when lever pressing was required in both multiple components; (c) when key pecking was required in both multiple components; and (d) when key pecking was required on one schedule and lever pressing was required on the concurrently-available schedule. Only the absolute level of responding was changed by different response requirements. Analyzed by the generalized matching law, performance under different response requirements resulted in a bias toward key pecking, and the measured response bias was the same in multiple and concurrent schedule arrangements. The bias in time measures obtained from concurrent schedule performance was reliably smaller than the obtained response biases. The sensitivity to reinforcement-rate changes was ordered: concurrent key-lever; multiple key-key; multiple lever-key; and, the least sensitive, multiple lever-lever. The results confirm that requirements of different topographical responses can be handled by the generalized matching law mainly in the bias parameter, but problems for this type of analysis may be caused by the changing sensitivity to reinforcement in multiple schedule performance as response requirements are changed.     

Methodological issues in prevention research: An introduction to the special issue

In recent years increased attention has been directed to prevention research as a means of solving the multitude of complex social and health problems which confront individuals and their societies. Abuse of substances, behavioral dysfunctions, violence, emotional disorders, educational failures, unwanted pregnancies and sexually transmitted diseases are but a few examples of these most difficult problems. As our recognition of the need for sound prevention strategies has grown, so has our sophistication in designing prevention research studies to evaluate the effectiveness of these new strategies. And that sophistication has brought new challenges, some of which are capable of stifling progress because of their complexity. This problem is certain to grow in importance as interventions with multiple components are used more frequently to meet the challenges of the complex social and health problems we face. This special issue evolved out of the recognition that prevention researchers are confronted by a myriad of difficult methodological issues which have inhibited progress in this area. The articles in the issue present innovative methodological solutions designed to overcome these problems so the field can move forward. Editor's Note: Dr. Edward Seidman edited Methodological Issues in Prevention Research while serving as Associate Editor for Methodology.     

部件启动范式下可成字部件的位置效应

可成字部件在汉字中的位置和功能多种多样。实验1采用部件启动范式考察在汉字识别中可成字部件在不同位置的功能。启动刺激为处于三种位置(主要义符位置、次要义符位置、声符位置)的可成字部件, 目标刺激为包含这三种位置可成字部件的汉字, 要求被试对目标字做词汇判断。实验2结合部件启动范式和视觉搜寻范式探查可成字部件在不同位置的功能。结果表明：(1)可成字部件处在声符位置时的启动效应强于处在义符位置时。(2)可成字部件作义符时的启动作用只出现在处于主要义符位置时。(3)处在声符位置的可成字部件启动不仅促进对包含声符位置部件的汉字的识别, 还促进对包含主要义符位置部件的汉字的识别, 但阻碍对包含次要义符位置部件的汉字的识别。(4)当启动部件处于次要义符位置时, 不影响对包含相关部件的汉字的识别。整个研究表明, 部件位置效应不仅包含部件位置对汉字识别的影响, 还包含部件位置频率对汉字识别的影响。     

Short-component multiple schedules: effects of relative reinforcement duration

Pigeons were exposed to multiple variable-interval 2-min variable-interval 2-min schedules of food presentation in which relative duration of food presentation was manipulated. When components alternated every 5 sec and were scheduled on separate response keys, relative response rates closely matched relative reinforcement duration in three of four pigeons. On the other hand, relative response rates were insensitive to relative reinforcement duration when components scheduled on a single response key alternated every 5 sec, and when components scheduled on separate response keys alternated every 2 min. Thus, both rapid alternation and spatial separation of components were necessary to produce approximate matching of relative responding to relative reinforcement duration. This finding contrasts with previous findings that only rapid component alternation is necessary for matching when relative rate of reinforcement is manipulated.     

The effects of component duration on multiple-schedule performance in closed and open economies.

Pigeons responded on multiple variable-interval variable-interval schedules of reinforcement in an open and a closed economy. Equal duration components were increased in duration while the component rates of reinforcement were held constant, the component schedules were reversed, and component duration was decreased. In the open economy, daily sessions were limited to 1 hr, and subjects were maintained at 80% of their free-feeding weights through supplemental feeding when necessary in their home cages. In the closed economy, subjects were housed in their experimental chambers and no deprivation regimen was enforced. Relative response rate decreased as components were lengthened in the open economy, whereas in the closed economy relative rate increased as components were lengthened. Response proportions overmatched reinforcer proportions to a greater extent at long component durations in the closed economy, but there was no systematic effect of component duration on responding in the open economy.     

Critical issues in the prevention of violence-related behavior in youth

Violence prevention programs with varying degrees of scientific support have proliferated in the United States and elsewhere. This paper previewed a broad range of programs involving youth, families, or systems that aimed to prevent or reduce violence-related behavior. The purpose of the review was to address critical issues concerning (1) target level of programming, (2) theory-driven versus problem-driven conceptualization, (3) cultural considerations, (4) developmental considerations, (5) intervention fidelity, and (6) outcome and impact assessment. Conclusions about these issues address tendencies and trends across programs.     

The importance of multiple exemplar instruction in the establishment of novel verbal behavior

According to traditional linguistic accounts language, and its generative nature, cannot be taught. From a behavior analytic perspective, language is like any other behavior; it is learned and amenable to change. Based upon Skinner's radical behavioral analysis of verbal behavior, specific procedures have been designed to promote novel verbal relations. However, despite the strength and utility of this approach, using behavioral principles to understand the generativity of language has been challenging. Dependent upon the specific theory (e.g., stimulus equivalence, relational frame theory, bidirectional naming) within the radical behavioral orientation, researchers arrange unique procedures to evaluate the variables responsible for this phenomenon. This paper presents the commonalities and differences of two procedures (i.e., multiple exemplar training, multiple exemplar instruction) with examples of research highlighting the use of both in producing generativity. Further, it describes how multiple exemplar instruction is independent from other procedures leading to this outcome, and concludes by providing recommendations for both research and practice.     

Meta-analysis of the effects of third-wave behavioural interventions on disordered eating and body image concerns: implications for eating disorder prevention

Third-wave behavioural interventions are increasingly popular for treating and preventing mental health conditions. Recently, researchers have begun testing whether these interventions can effectively targeting eating disorder risk factors (disordered eating, body image concerns). This meta-analysis examined whether third-wave behavioural interventions (acceptance and commitment therapy; dialectical behaviour therapy; mindfulness-based interventions; compassion-focused therapy) show potential for being effective eating disorder prevention programs, by testing their effects on eating disorder risk factors in samples without an eating disorder. Twenty-four studies (13 randomized trials) were included. Most studies delivered selective prevention programs (i.e. participants who reported elevated risk factor). Third-wave interventions led to significant pre–post (g = 0.59; 95% CI = 0.43, 0.75) and follow-up (g = 0.83; 95% CI = 0.38, 1.28) improvements in disordered eating, and significant pre–post improvements in body image (g = 0.35; 95% CI = 0.13, 0.56). DBT-based interventions were associated with the largest effects. Third-wave interventions were also significantly more efficacious than wait-lists (g = 0.39; 95% CI = 0.09, 0.69) in reducing disordered eating, but did not differ to other interventions (g = 0.25; 95% CI = –0.06, 0.57). Preliminary evidence suggests that third-wave interventions may have a beneficial effect in ameliorating eating disorder risk.     

Optimal trade-offs of multiple factors in transfer pricing problems

Transfer pricing problems have been extensively researched by a number of scholars. It is well recognized that transfer pricing problems have a multiple-criteria (objectives) feature and can be formulated as a model of multiple-criteria linear programming. However, few methods have the capability of dealing with all possible optimal trade-offs of multiple criteria in optimal solutions of the models. In this paper a linear multiple-factor model is developed to provide managers with a more systematic and comprehensive scenario of all possible optimal transfer prices depending on both multiple criteria and multiple constraint levels. The trade-offs of all possible optimal transfer prices can be used as a basis for managers of a corporation to make a high-quality decision in selecting their transfer pricing systems for business competition. © 1998 John Wiley & Sons, Ltd.     

Randomization procedures in single‐case intervention research contexts: (Some of) “the rest of the story”

Following up on articles recently published in this journal, the present contribution tells (some of) “the rest of the story” about the value of randomization in single‐case intervention research investigations. Invoking principles of internal, statistical‐conclusion, and external validity, we begin by emphasizing the critical distinction between design randomization and analysis randomization, along with the necessary correspondence between the two. Four different types of single‐case design‐and‐analysis randomization are then discussed. The persistent negative influence of serially dependent single‐case outcome observations is highlighted, accompanied by examples of inappropriate applications of parametric and nonparametric tests that have appeared in the literature. We conclude by presenting valid applications of single‐case randomization procedures in various single‐case intervention contexts, with specific reference to a freely available Excel‐based software package that can be accessed to incorporate the present randomization schemes into a wide variety of single‐case intervention designs and analyses.     

Extensions of a versatile randomization test for assessing single-case intervention effects

The purpose of the present study was to investigate the statistical properties of two extensions of the Levin-Wampold (1999) single-case simultaneous start-point model's comparative effectiveness randomization test. The two extensions were (a) adapting the test to situations where there are more than two different intervention conditions and (b) examining the test's performance in classroom-based intervention situations, where the number of time periods (and associated outcome observations) is much smaller than in the contexts for which the test was originally developed. Various Monte Carlo sampling situations were investigated, including from one to five participant blocks per condition and differing numbers of time periods, potential intervention start points, degrees of within-phase autocorrelation, and effect sizes. For all situations, it was found that the Type I error probability of the randomization test was maintained at an acceptable level. With a few notable exceptions, respectable power was observed only in situations where the numbers of observations and potential intervention start points were relatively large, effect sizes were large, and the degree of within-phase autocorrelation was relatively low. It was concluded that the comparative effectiveness randomization test, with its desirable internal validity and statistical-conclusion validity features, is a versatile analytic tool that can be incorporated into a variety of single-case school psychology intervention research situations.     

Alternating least squares algorithms for simultaneous components analysis with equal component weight matrices in two or more populations

Millsap and Meredith (1988) have developed a generalization of principal components analysis for the simultaneous analysis of a number of variables observed in several populations or on several occasions. The algorithm they provide has some disadvantages. The present paper offers two alternating least squares algorithms for their method, suitable for small and large data sets, respectively. Lower and upper bounds are given for the loss function to be minimized in the Millsap and Meredith method. These can serve to indicate whether or not a global optimum for the simultaneous components analysis problem has been attained.Financial support by the Netherlands organization for scientific research (NWO) is gratefully acknowledged.     

Determining the number of components from the matrix of partial correlations

A common problem for both principal component analysis and image component analysis is determining how many components to retain. A number of solutions have been proposed, none of which is totally satisfactory. An alternative solution which employs a matrix of partial correlations is considered. No components are extracted after the average squared partial correlation reaches a minimum. This approach gives an exact stopping point, has a direct operational interpretation, and can be applied to any type of component analysis. The method is most appropriate when component analysis is employed as an alternative to, or a first-stage solution for, factor analysis.     

Evaluation of the effects of a childhood depression prevention program

The study aimed to design and evaluate a program for the prevention of childhood depression (“Pozik-Bizi” [in English, “Live-Happily”]), comparing its effects with a socio-emotional intervention program based on cooperative play. The sample comprised 420 students aged 7 to 10?years from the Basque Country, 51.9% were randomly assigned to the experimental condition (“Pozik-Bizi”) program and 48.1% to the control group (“Play program”). Using a pretest-posttest repeated measures experimental design, 7 evaluation instruments were administered. When comparing the two interventions, it was confirmed that those who participated in the “Pozik-Bizi” program significantly decreased their level of clinical maladjustment, school maladjustment, emotional, and behavioral problems, and they increased positive behaviors that inhibit depression. However, the cooperative play program improved self-concept and social skills significantly more than the “Pozik-Bizi” program. The effect size in all the variables was small. The discussion analyzes the effectiveness of specific programs of prevention of childhood depression versus global programs of social-emotional development. This work provides a program to prevent childhood depression that has been shown to be effective in the reduction of clinical variables. In addition, this study confirms the positive potential of programs of cooperative play, to increase self-concept and social skills.     

An analysis and synthesis of multiple correspondence analysis,optimal scaling,dual scaling,homogeneity analysis and other methods for quantifying categorical multivariate data

We discuss a variety of methods for quantifying categorical multivariate data. These methods have been proposed in many different countries, by many different authors, under many different names. In the first major section of the paper we analyze the many different methods and show that they all lead to the same equations for analyzing the same data. In the second major section of the paper we introduce the notion of a duality diagram, and use this diagram to synthesize the many superficially different methods into a single method.The ideas in this paper were worked out by the first author, with some suggestions provided by the second. The current version of this paper has evolved from three previous versions, the first two written by the first author.